GB2041506A

GB2041506A - Solar lighting system

Info

Publication number: GB2041506A
Application number: GB7904093A
Authority: GB
Original assignee: WU SHING HSIUNG
Current assignee: WU SHING HSIUNG
Priority date: 1979-02-06
Filing date: 1979-02-06
Publication date: 1980-09-10

Abstract

A solar lighting system includes a light transmitting tube 4 extending through a building roof D, and a planoconvex lens 3 and a planoconcave lens 6 located at the entrance and exit respectively of the tube 4. A hemispherical array of four convex lenses 1 and conic convergent tubes 2 is located at the tube entrance, and a fluorescent screen bulb 7 is mounted at the tube exit. An illumination controller 5 is mounted in the tube 4 slightly upstream of the tube exit. In operation, sun or moon-light incident on the hemispherical array is directed down the tube 4 and onto the bulb 7 which fluoresces to provide the required illumination. <IMAGE>

Description

SPECIFICATION A solar lighting system TECHNICAL FIELD The present invention relates to a solar lighting system. In this Specification, the expression "solar lighting system" means a system employing light from the sun or the moon.

BACKGROUND ART Artificial lighting is generally produced by either an incandescent lamp or a fluorescent lamp. An advantage of the fluorescent lamp is that it consumes less power and operates at a lower temperature than the incandescent lamp, and consequently fluorescent lamps are frequently used in schools, offices and factories. Lighting systems for providing indoor illumination are generally arranged to provide an interior intensity of illumination in the range from 50 to 100 candle-power which equals approximately 10% of the intensity of illumination of sun-light in shady conditions.

One problem that arises with the aforementioned lighting systems is that they require a source of electrical power, and they do not possess the beneficial effects of sun-light.

STATEMENT OF INVENTION AND ADVAN TAGES It is an aim of the invention to provide a lighting system to alleviate the aforementioned problem, and accordingly there is provided a solar lighting system comprising a light transmitting tube and an optical arrangement to direct the sun-light through said tube onto a fluorescent receiver.

It is to be understood that in this Specification any reference to sun-light also includes moon-light.

The said optical arrangement may include at least one convex lens, and a conic convergent tube to receive light from said convex lens. A preferred lighting system of the invention includes a plurality of convex lenses and associated conic convergent tubes which are arranged like a hemisphere for location in the path traversed by the sun from sunrise to sunset.

The system may include a plano-convex lens located at the entrance to the light transmitting tube and a plano-concave lens to direct light from the tube onto the fluorescent receiver. In one system of the invention the fluorescent receiver may be in the form of a bulb, and the system may include an illumination controller to control the light intensity directed onto the fluorescent bulb.

THE DRAWING An embodiment of the invention will now be described by way of example with reference to the accompanying illustrative drawing which is a side elevation partly in section of one solar lighting system of the invention.

DETAILED DESCRIPTION OF THE DRAWING Referring to the drawing, one solar lighting system of the invention includes a light transmitting tube 4 mounted so as to extend through the roof D of a building. Four conic convergent tubes 2 are located adjacent to one another with their apices at the entrance to the light transmitting tube 4. Four convex lenses 1 are mounted at the entrances to these tubes 2, and the tubes 2 and convex lenses 1 constitute a hemispherical array facing the path traversed by the sun during the daytime. A plano-convex lens 3 is located at the entrance to the light transmitting tube 4 and at the apices of the conic convergent tubes 2. The array A is arranged so that during daylight at least one of the convex lenses 1 is facing the sun either directly or almost directly.The convex lenses 1, the tubes 2 and the plano-convex lens 3 are arranged so that light incident on one or more of the convex lenses 1 is focused onto the plano-convex lens 3 and directed down the light transmitting tube 4. In order to reduce light loss, the inner surface of each tube 2 and the tube 4 is made of a material of high light reflectivity such as, for example, silver.

A fluorescent screen bulb 7 is mounted at the exit of the tube 4, and a plano-concave lens 6 is also mounted at the exit of the tube 4 to direct light from the tube 4 onto the bulb 7. An illumination controller 5, similar to a camera diaphrahm, is mounted in the tube 4 slightly upstream of the tube exit.

In operation, the sun or moon-light incident on the convex lenses 1 is focused onto the plano convex lens 3 and is directed down the tube 4. This light passes through the illumination controller 5 and is directed by the planoconcave lens 6 onto the bulb 7 which is coated with fluorescent powder. The light incident on the bulb 7 causes this powder to fluoresce thereby providing the required illumination.

Although the described and illustrated lighting system is installed in the roof of a building to light up a room, it is envisaged that a lighting system of the invention will have other applications, such as for example, a medical lamp to make use of the beneficial effects of sun-light on the human body.

1. A solar lighting system comprising a light transmitting tube and an optical arrangement to direct sun-light through said tube onto a fluorescent receiver.

2. A system as claimed in Claim 1, in which said optical arrangement includes at least one convex lens.

3. A system as claimed in Claim 2, in which said optical arrangement includes a conic convergent tube.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION A solar lighting system TECHNICAL FIELD The present invention relates to a solar lighting system. In this Specification, the expression "solar lighting system" means a system employing light from the sun or the moon. BACKGROUND ART Artificial lighting is generally produced by either an incandescent lamp or a fluorescent lamp. An advantage of the fluorescent lamp is that it consumes less power and operates at a lower temperature than the incandescent lamp, and consequently fluorescent lamps are frequently used in schools, offices and factories. Lighting systems for providing indoor illumination are generally arranged to provide an interior intensity of illumination in the range from 50 to 100 candle-power which equals approximately 10% of the intensity of illumination of sun-light in shady conditions. One problem that arises with the aforementioned lighting systems is that they require a source of electrical power, and they do not possess the beneficial effects of sun-light. STATEMENT OF INVENTION AND ADVAN TAGES It is an aim of the invention to provide a lighting system to alleviate the aforementioned problem, and accordingly there is provided a solar lighting system comprising a light transmitting tube and an optical arrangement to direct the sun-light through said tube onto a fluorescent receiver. It is to be understood that in this Specification any reference to sun-light also includes moon-light. The said optical arrangement may include at least one convex lens, and a conic convergent tube to receive light from said convex lens. A preferred lighting system of the invention includes a plurality of convex lenses and associated conic convergent tubes which are arranged like a hemisphere for location in the path traversed by the sun from sunrise to sunset. The system may include a plano-convex lens located at the entrance to the light transmitting tube and a plano-concave lens to direct light from the tube onto the fluorescent receiver. In one system of the invention the fluorescent receiver may be in the form of a bulb, and the system may include an illumination controller to control the light intensity directed onto the fluorescent bulb. THE DRAWING An embodiment of the invention will now be described by way of example with reference to the accompanying illustrative drawing which is a side elevation partly in section of one solar lighting system of the invention. DETAILED DESCRIPTION OF THE DRAWING Referring to the drawing, one solar lighting system of the invention includes a light transmitting tube 4 mounted so as to extend through the roof D of a building. Four conic convergent tubes 2 are located adjacent to one another with their apices at the entrance to the light transmitting tube 4. Four convex lenses 1 are mounted at the entrances to these tubes 2, and the tubes 2 and convex lenses 1 constitute a hemispherical array facing the path traversed by the sun during the daytime. A plano-convex lens 3 is located at the entrance to the light transmitting tube 4 and at the apices of the conic convergent tubes 2. The array A is arranged so that during daylight at least one of the convex lenses 1 is facing the sun either directly or almost directly.The convex lenses 1, the tubes 2 and the plano-convex lens 3 are arranged so that light incident on one or more of the convex lenses 1 is focused onto the plano-convex lens 3 and directed down the light transmitting tube 4. In order to reduce light loss, the inner surface of each tube 2 and the tube 4 is made of a material of high light reflectivity such as, for example, silver. A fluorescent screen bulb 7 is mounted at the exit of the tube 4, and a plano-concave lens 6 is also mounted at the exit of the tube 4 to direct light from the tube 4 onto the bulb 7. An illumination controller 5, similar to a camera diaphrahm, is mounted in the tube 4 slightly upstream of the tube exit. In operation, the sun or moon-light incident on the convex lenses 1 is focused onto the plano convex lens 3 and is directed down the tube 4. This light passes through the illumination controller 5 and is directed by the planoconcave lens 6 onto the bulb 7 which is coated with fluorescent powder. The light incident on the bulb 7 causes this powder to fluoresce thereby providing the required illumination. Although the described and illustrated lighting system is installed in the roof of a building to light up a room, it is envisaged that a lighting system of the invention will have other applications, such as for example, a medical lamp to make use of the beneficial effects of sun-light on the human body. CLAIMS

4. A system as claimed in Claim 3, including a plurality of convex lenses and conic convergent tubes arranged like a hemisphere for location in the sun's path.

5. A system as claimed in any preceding Claim, including a plano-convex lens located at the entrance to the light transmitting tube.

6. A system as claimed in any preceding Claim, including a plano-concave lens to direct light from the light transmitting tube onto the fluorescent receiver.

7. A system as claimed in any preceding Claim, including an illumination controller to control the intensity of the light directed onto the fluorescent receiver.

8. A system as claimed in any preceding Claim, in which the fluorescent receiver is a bulb.

9. A solar lighting system substantially as herein described, and illustrated in the accompanying drawing.